Apparatus for pulp sampling



May 22, 1956 w. T. MARTIN APPARATUS FOR PULP SAMPLING Filed Aug. 12,1955 FIG. 3

FIG. 5

DIIIIIIIIIIH! 40 FIG. 2

INVENTOR. WILLIAM T. MARTIN United States Patent APPARATUS FOR PULPSAMPLING William T. Martin, International Falls, .Minn., assignor tolVIinnesota and Ontario Paper Company, Minneapolis,

Application August 12, 19'53,SerialNo. 373,844

4 Claims. (Cl. 73-421) This invention relates to improvements inapparatus for sampling pulp during the digesting of lignocellulosematerial.

An object of this invention is to provide the means of determiningprogress of1he digestion of lignocellulose material during the digestingperiod without substantial loss of pressure and/0r digestion chemicals.

Other and further objects of the invention and the advantages of thesame will be pointed out hereinafter and indicated "in the appendedclaims or will be obvious to one skilled in the art upon understandingthe present disclosures.

For the purpose of the application there has been set forth oneparticular structure but it is to be understood that it is presented forillustrative purposes only and is not to be accorded any interpretationsuch as might have the effect of limiting what is claimed as theinvention short of its true and comprehensive scope in the art.

For the manufacture of chemical pulp it is necessary (for the cookingliquor to penetrate the lignocellulose material such as wood) to reducethe chips to a size of about /2 inch to 1 inch long and about A; to inchthick. These chips are loaded into a suitable digester with the properamount of digesting chemical. The digester after loading is closed andtemperature and pressure applied until complete cooking has beenaccomplished. The time required for digesting varies with the types ofpulp to be produced, types of lignocellulose material being cooked andso forth. The time for digesting varies from a few hours up to 10 and 12or more hours. It is desirable to check the progress of digestion beforethe cooking cycle is complete. Heretofore it has been very difiicult tocheck the progress of digestion during cooking. In most instances nocheck of the digestion has been made until the lignocellulose materialis discharge from the digester. At such time it is, of course, too lateto do anything about the cooking. In accordance with the invention thelignocellulose material may be checked from time to time duringdigestion and if any alteration in the cooking cycle is required it maybe accomplished.

In the drawings Figure 1 is a side elevational view of a digestingvessel with parts broken away;

Figure 2 is a side elevational view of a pulp sampling device by whichthe process may be carried out;

Figure 3 is a top plan view of the same;

Figure 4 is a view of a shower plate which is located adjacent the topof the pulp sampling device;

Figure 5 is a top plan view of a pulp gathering tray;

Figure 6 is a side elevational view of the same; and

Figure 7 is a sectional view through the sampling device shown in Figure2.

The lignocellulose material, such as wood, in the proper form is fedinto the digester 10 along with the digesting liquor. The normalprocedure for cooking the lignocellulose material is carried out andduring the digesting cycle sample of the material undergoing cooking isobtained by opening valve 14 in line 12 suitably connected to thedigester. The pressure in the digester forces the material from thedigester through line 12 into member '16 and then into the samplingdevice 18 tangentially to the walls thereof. At the time the valve 14 isopen, water supplied under pressure is admitted through pipe 22 into theupper portion of the sampling device 18. The water passes throughopenings '30 in shower plate 26.

The sampling device 18 includes water receiving space 24 formed byshower plate 26 and top 28. Water is received in this space throughconduit 22. Member 20 is secured to the top 28 and forms the inner wallsof the shower space 24. The member 20 extends a distance into the space17 and restricts the area into which the material is first received fromthe digester 10. In the lower end of space 17 is secured funnel-likemember 34. Below the funnel-like member 34 is space 38 which receivesthe lignocellulose receiving tray 42. The sampling member 13 is providedwith an opening 32 into which the tray 42'may be inserted and removed.Member 37 may be used for supporting the tray 42 in proper position-inspace 38. Water from space 38 leaves the sampling device by dischargeend 40.

The shower plate 26 is provided with a series of apertures 30. Thedrawing shows two rows of apertures but it is to be understood that anynumber of openings may be provided as long as sufiicient shower watercan pass therethrough. It is preferred that the opening 32 be providedwith a lip 36 to prevent splashing out of the openings of pulp andwater. The tray 42 is provided with a foraminous bottom member 44. Thepulp is deposited on the foraminous member and the water passes on tothe discharge end 40. Tray 42 may be provided with a suitable handle 46.

In operation when a sample is desired the valve 14 is opened and thelignocellulose material from the digester is forced under pressure intothe sampler 18 tangentially to the walls of the sampler and the member20. The water flows into the shower space and passes through theopenings 30 causing the cyclone lignocellulose material to fall throughthe space 17. The material passing through the restricted open end ofthe funnel-like member 34 results in depositing the material upon theforaminous bottom of the tray 42 without passing through the opening 32.The Water which passes through the tray is discharged through the end 49which is usually connected to a suitable discharge line.

It is to be understood that the valve 14 is only open momentarily, forexample, a few seconds each time so that the steam and gas releaseremains at a minimum. It is also to be understood that the sample fromthe digester may be blown into the sampler without the Water being on atthe same time. The water for washing may be turned on after the samplehas been taken from the digester, although the simultaneous obtaining ofa sample and washing is the preferred method. If desired a vent could beused in connection with the sampler and if such vent is employed itwould be secured to the top about the mid-portion of the member 20.

What is claimed is:

1. A device of the class described comprising a cylindrical vesselhaving a closed top and an opening on one side spaced from the top forreceiving a foraminous bottom tray, a smaller diameter cylindricalmember secured to the top and extending inside the vessel for less thanhalf the length of the said Vessel, a shower plate secured to the wallsof the vessel and spaced apart from the top to provide a water space,means for supplying water to the Water space, a funnel-like membersecured inside the cylindrical vessel and spaced apart from the ends ofthe smaller diameter cylindrical member, said funnel-like member alignedsubstantially axially with the axis of the vessel and below the bottomof the smaller diameter cylindrical member and a foraminous collectingmember positioned below the funnel-like member and a water discharge atone end of the cylindrical vessel and below the foraminous collectingmember.

2. An upright cylindrical vessel having a closed top, a cylindricalmember of about one-half the diameter of the cylindrical vessel and lessthan one-half the length secured to the top and extending into thevessel, a shower plate spaced from the top and secured between the wallof the cylindrical vessel and the cylindrical member, means forsupplying water above the shower plate, means for discharginglignocellulose material below the shower plate and between the walls ofthe cylindrical vessel and the cylindrical member, a funnel-like memberpositioned substantially in axial alignment with the axis of the vesseland below and spaced apart from the lower end of the cylindrical member,and a screen bottom tray removably secured in the cylindrical vessel andbelow the funnelshaped member.

3. A sampler adapted to be placed in controlled communication with apulp digester, the sampler comprising an upright closed top cylindricalvessel, a perforated plate secured to the vessel walls and spaced apartfrom the top to provide a water receiving space, means for supplyingwater to the water space, means for discharging lignocellulose materialtangentially to the walls of the sampler below the perforated plate, afunnel-like member positioned in the sampler and spaced apart from theshower plate, said funnel-like member being in substantially axialalignment with the axis of the vessel, and a removable foraminous bottomtray positioned below the funnelshaped member for receivinglignocellulose material and permitting water to pass therethrough.

4. A cylindrical vessel having a closed end and an open end, a smallerdiameter cylindrical member secured within the vessel and to the closedend, said smaller diameter member of considerably shorter length thanthe vessel, a perforated plate spaced apart from the closed end of thevessel and secured between the walls of the vessel and the smallerdiameter cylindrical member to provide a water receiving space, meansfor supplying Water to said water receiving space, means for discharginglignocellulose material below the perforated plate tangentially to thewalls of the cylindrical vessel, a removable foraminous bottom tray forcollecting lignocellulose material, said tray positioned in thecylindrical vessel between the perforated plate and the open end of thecylindrical vessel.

References Cited in the file of this patent UNITED STATES PATENTS2,615,339 Holgersson et al Oct. 28, 1952 FOREIGN PATENTS 376,678 GermanyJune 1, 1923

1. A DEVICE OF THE CLASS DESCRIBED COMPRISING A CYLINDRICAL VESSELHAVING A CLOSED TOP AND AN OPENING ON ONE SIDE SPACED FROM THE TOP FORRECEIVING A FORAMINOUS BOTTOM TRAY, A SMALLER DIAMETER CYLINDRICALMEMBER SECURED TO THE TOP AND EXTENDING INSIDE THE VESSEL FOR LESS THANHALF THE LENGTH OF THE SAID VESSEL, A SHOWER PLATE SECURED TO THE WALLSOF THE VESSEL AND SPACED APART FROM THE TOP TO PROVIDE A WATER SPACE,MEANS FOR SUPPLYING WATER TO THE WATER SPACE, A FUNNEL-LIKE MEMBERSECURED INSIDE THE CYLINDRICAL VESSEL AND SPACED APART FROM THE ENDS OFTHE SMALLER DIAMETER CYLINDRICAL MEMBER, SAID FUNNEL-LIKE MEMBER ALIGNEDSUBSTANTIALLY AXIALLY WITH THE AXIS OF THE VESSEL AND BELOW THE BOTTOMOF THE SMALLER DIAMETER CYLINDRICAL MEMBER AND A FORAMINOUS COLLECTINGMEMBER POSITIONED BELOW THE FUNNEL-LIKE MEMBER AND A WATER DISCHARGE ATONE END OF THE CYLINDRICAL VESSEL AND BELOW THE FORAMINOUS COLLECTINGMEMBER.